"Public health investigators are working with shelter staff to determine if there are any significant exposures at the convention center that call for re-testing or evaluation," Bailey said. "Persons in isolation will be kept off-site until it is deemed safe for them to return to the shelter or be released to a permanent housing solution based on CDC guidelines."

Testing began on April 16 at the emergency homeless shelter in the convention center as part of a proactive effort to detect anyone who may have COVID-19 but has not shown symptoms, Bailey said.

"This proactive testing helped staff identify cases that otherwise could have been missed and protect the health of all working and taking up shelter here," San Diego Mayor Kevin Faulconer said. "Appropriate action was taken because we were prepared for the real possibility that individuals who may not feel or appear ill can still have COVID-19."

Supervisor Nathan Fletcher said a testing protocol was put in place to provide a high level of protection to anyone who tests positive.

"While these two cases represent a small percentage of the total tests conducted, it reinforces the need to provide testing, tracing and treatment. The protocol to manage these situations was well thought out and is being properly followed."

Homeless people who were already in shelters began moving into the convention center April 1.

On April 10, outreach staff began bringing in people living on the streets into the convention center.